"The Natural Philosopher" wrote in message
...
salesguy wrote:
Rockwool does slightly less than **** all for sound insulation, and in
walls, it tends to fall down, which is why its not recommended for
thermal much either.


With respect, that is ********. Acoustic insulation in plasterboard
partitions is either rock fibre, or more normally, glass fibre. The
normal product used is Acoustic Partition Roll (APR) that is a high
density glass matt.
*************

HIGH DENSITY.

Tell me what is HUGH DENSITY about rockwool.


Rock fibre can be used as well, due to it's higher densities.

As to cavities, correctly installed glass or rock will do the job, and
will not sag or slump over time.

Boards are fine, but if there are *any* gaps the insulation is useless.



Which is what I said.
SalesGuy
http://www.knaufinsulation.co.uk/out.../page_326.html


Anything from 33kg/m3 to 200kg/m3.

That is high compared to glass.

My point above refers to thermal insulation - any gaps between foam boards
render the insulation ineffective.

Mineral fibre (glass or rock) is the best acoustic insulant in this
situation.

I agree block would be better, but that solution is hardly ever used for
internal non-load bearing walls.

http://www.knaufinsulation.co.uk/out.../page_232.html

for options.....


SalesGuy